Hi, New to this forum, and was hoping to get some help. I would like to get my old truck running again, and have been talking to a local shop regarding the motor. After going through my options, I liked the idea of rebuilding the original 400 motor it came with to keep it as original as possible. Have seen this motor is gaining interest. The guy at the shop did tell me that I should make sure that my engine was built after March 2 1977 though, as a flaw in the block casting caused a lot of cracks in the water jacket. I did some research and read that the bottom end of the block was beefed up for the truck application due to them being mated to a std tranny, but he said there should be a casting date on the block someplace to be sure mine doesn't have the flaw. So my question is. Does anyone know the location of the casting date number on my engine. Any help would be great thanks.